Geographic isolation drives divergence of uncorrelated genetic and song variation in the Ruddy-capped Nightingale-Thrush (Catharus frantzii; Aves: Turdidae) q Marco F. Ortiz-Ramírez a,b,⇑ , Michael J. Andersen c,d,1 , Alejandro Zaldívar-Riverón e , Juan Francisco Ornelas f , Adolfo G. Navarro-Sigüenza a a Museo de Zoología, Facultad de Ciencias, UNAM, Apartado Postal 70-399, México, D. F. 04510, Mexico b Posgrado en Ciencias Biológicas, UNAM, Mexico c Department of Ecology and Evolutionary Biology and Biodiversity Institute, University of Kansas, Lawrence, KS 66045, USA d Department of Ornithology, American Museum of Natural History, New York, NY 10024, USA e Colección Nacional de Insectos, Instituto de Biología, UNAM, Apartado Postal 70-233, México, D. F. 04510, Mexico f Departamento de Biología Evolutiva, Instituto de Ecología AC, Xalapa, Veracruz, Mexico article info Article history: Received 14 November 2014 Revised 13 August 2015 Accepted 17 August 2015 Available online 22 August 2015 Keywords: Phylogeography Song variation Catharus Mesoamerica abstract Montane barriers influence the evolutionary history of lineages by promoting isolation of populations. The effects of these historical processes are evident in patterns of differentiation among extant popula- tions, which are often expressed as genetic and behavioral variation between populations. We investi- gated the effects of geographic barriers on the evolutionary history of a Mesoamerican bird by studying patterns of genetic and vocal variation in the Ruddy-capped Nightingale-Thrush (Turdidae: Catharus frantzii), a non-migratory oscine bird that inhabits montane forests from central Mexico to Panama. We reconstructed the phylogeographic history and estimated divergence times between popu- lations using Bayesian and maximum likelihood methods. We found strong support for the existence of four mitochondrial lineages of C. frantzii corresponding to isolated mountain ranges: Sierra Madre Oriental; Sierra Madre del Sur; the highlands of Chiapas, Guatemala, and El Salvador; and the Talamanca Cordillera. Vocal features in C. frantzii were highly variable among the four observed clades, but vocal variation and genetic variation were uncorrelated. Song variation in C. frantzii suggests that sex- ual selection and cultural drift could be important factors driving song differentiation in C. frantzii. Ó 2015 Elsevier Inc. All rights reserved. 1. Introduction Diversification of montane taxa is an evolutionary phenomenon attributed to geographical isolation of populations and ecological factors that promote divergence by limiting exchange of genetic and cultural information (Price, 2008; Fjeldså et al., 2012). Once populations are geographically isolated, they may diverge in response to different ecologically based selection pressures. The rate of divergence may be accelerated when populations occupy different environments with different selection pressures (Orr and Smith, 1998; Lachlan and Servedio, 2004; Catchpole and Slater, 2008; Shaw and Mullen, 2011). The maintenance of barriers to gene flow is of considerable importance to understand specia- tion in montane systems. Geographic isolation may also facilitate development of behav- ioral barriers to gene flow (West-Eberhard, 1983; Parker et al., 2012). Behavioral barriers are of particular interest in oscine song- birds, a lineage that is influenced by cultural evolution via song learning and sexual selection. As such, behavioral barriers have the potential to affect mate recognition and promote speciation in oscines (Lynch, 1996; Slabbekoorn and Smith, 2002b; Lachlan and Servedio, 2004; Podos and Warren, 2007; Catchpole and Slater, 2008; Price, 2008; Grant and Grant, 2010; Rowell and Servedio, 2012; Verzijden et al., 2012; Vokurková et al., 2013). Vocalizations are useful characters for species diagnosis and delimitation in birds, especially across phylogeographic breaks (Payne, 1986; Isler et al., 1998; Tubaro, 1999). They can be used http://dx.doi.org/10.1016/j.ympev.2015.08.017 1055-7903/Ó 2015 Elsevier Inc. All rights reserved. q This paper was edited by the Associate Editor C. Krajewski. ⇑ Corresponding author at: Museo de Zoología, Facultad de Ciencias, UNAM, Apartado Postal 70-399, México, D. F. 04510, Mexico. E-mail address: marcoortiz@ciencias.unam.mx (M.F. Ortiz-Ramírez). 1 Present address: Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM 87108, USA. Molecular Phylogenetics and Evolution 94 (2016) 74–86 Contents lists available at ScienceDirect Molecular Phylogenetics and Evolution journal homepage: www.elsevier.com/locate/ympev